Psychomotor Stimulants Flashcards
Cocaine
Alkaloid found in the leaves of the coca shrub (stimulating and hunger-reducing effects).
Oral admnistration of cocaine
- Includes coca leaves & beverages. (water soluble).
- Slower absorption.
Intranasal administration of cocaine
Slower absorption.
Iv Injection administration of cocaine
Extremely rapid absorption & higher concentration.
Inhalation administration of cocaine
1) freebasing: conversion of cocaine into its alkaline form to smoke.
2) crack: hardened cocaine/baking soda mixture that is smoked.
- strong addiction potential
- fat soluble –> rapid absorption.
Cocathelyene
metabolism produced when alcohol and cocaine produce are taken together.
What neurotransmitters does cocaine interact with?
Cocaine blocks the reuptake of DA, NE, and 5-HT.
How does cocaine act?
Cocaine binds to transporters & inhibits their function, leading to increased neurotransmitter levels in synaptic cleft & increase in transmission at synapses.
Which neurotransmitter is most important in reinforcing value?
Blockade of DA reuptake is most important for cocaine’s stimulating, reinforcing, and addictive properties.
Cognitive-Behavioural Effects
- Feelings of euphoria & heightened energy
- Increases sociability & aggressive behaviour.
- Repetitive picking/scratching.
- Cocaine-induced psychosis.
Sympathomimetic
cocaine produces symptoms of sympathetic nervous system activation (tachycardia, vasoconstriction, hypertension & hyperthermia).
- more averse effects are seizures, heart failure, stroke, brain hemorrhage.
tachycardia
increased heart rate
vasoconstriction
narrowing of blood vessels
hypertension
increased blood pressure
Three Factors Affect Positive Reinforcement
- ) Bioavailability
- ) Immediacy
- ) Baseline DA levels
Bioavailability
Once 40 to 60% of DAT occupancy is attained following cocaine administration, individual may feel a drug-induced high.
Immediacy
Smoking/Iv injection lead to quick drug entry into the brain & rapid DAT occupancy.
- more likely to produce an intense high than orally/intranasally.
Baseline DA levels
high levels of baseline DA release = greater effects of cocaine (because of higher concentration of DA molecules in synaptic cleft).
Experimentation
- Use of other drugs may lead to cocaine use.
- People usually begin by taking cocaine intranasally.
- Strong anxiety response may stop further experimentation.
Use/Abuse
- 10-15% of initial intranasal users become cocaine abusers.
- Reinforcement may be increased by social responses from friends.
- Legal consequences may inhibit further use.
Cocaine binges
periods of repeated cocaine use lasting from hours to days with little/no sleep.
Incubation
craving and relapse to cocaine increase overtime.
Three Phases of Binges
- ) Crash → exhaustion & depressed mood.
- ) Withdrawal → include anhedonia, anergia (lack of energy), anxiety, & growing craving increases risk of relapse.
- ) Extinction → symptoms subside.
Sensitization
Can be caused by just a few exposures.
- ) induction: sensitization is established
- ) expression: sensitized response is manifested.